Electromagnetic Rocking Chair

ABSTRACT

An electromagnetic rocking chair is disclosed. The electromagnetic rocking chair includes a fixing part, a moving part being moveable relative to the fixing part, at least two electromagnets disposed on the fixing part, and at least one permanent magnet disposed on the moving part. When the moving magnet moves to a position over the fixed magnet, the fixed magnet is electrified to produce repulsion forces due to homopolar repulsion, whereby the repulsion forces and the inertial force generated during the course of movement of the moving magnet can move the electromagnetic rocking chair smoothly.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. application Ser. No. 12/871,907 filed on Aug. 31, 2010, the disclosure of which is incorporated by reference herein in its entirety.

FIELD

The present invention relates to rocking chairs, and more particularly to an electromagnetic rocking chair.

BACKGROUND

An electric cradle is an electrical device for improving a traditional cradle by adding a power system, which can reduce the heavy labor of parents in taking care of a baby by automating the rocking motion of the traditional cradle. The rocking motion is very familiar to babies. For example, before birth, the fetus experiences a rocking motion when floating in the amniotic fluid of the mother's womb, such as when the mother is walking, or when the mother changes body positioning from standing, sitting or lying down. This type of stimulus can be sensed by the fetus and is believed to promote brain development. When the baby is born, the baby may be at unease, because the rocking stimulus experienced in the mother's womb is suddenly removed. It has been demonstrated that regularly rocking the baby can speed up development of the brain, and that the weight of the brain can double in one year, primarily in the brain's neocortex, which plays a critical role in development of the baby's IQ.

The conventional electric rocking chair is rocked by a motor which is generally complicated, noisy and prone to failure. An electromagnetic rocking chair has been developed to solve the above problems in a conventional electric rocking chair. An electromagnetic rocking chair is disclosed in U.S. patent application Ser. No. 12/871,907 filed on Aug. 31, 2010, the disclosure of which is incorporated by reference herein in its entirety. U.S. patent application Ser. No. 12/871,907 describes an electromagnetic rocking chair that includes a base, a chair seat, two fixed rods, and two suspension rods. Each of the fixed rods has a lower end fixed on one end of the base, and a transverse shaft is fixed on both upper ends of the fixed rods. An upper end of the respective suspension rods is pivotally connected to the transverse shaft, and the chair seat is disposed between the two suspension rods. A permanent magnet is disposed at the lower end of one of the suspension rods, and under the permanent magnet are disposed two electromagnets fixed on the base. On the base are further fixed two displacement sensors. The two electromagnets and two displacement sensors are connected to a control circuit on a circuit board. The electromagnetic rocking chair has advantages of simple and reasonable structure design, stable running, no noise, adjusting rocking amplitude and the like.

SUMMARY

The present invention relates to an electromagnetic rocking chair having a large load-driving force that is capable of being smoothly started up even when the center of gravity of the moving part is deviated. The electromagnetic rocking chair includes a fixing part, a moving part moveable relative to the fixing part, and a control module for controlling at least one magnetic force exerted on the moving part. At least two fixed magnets are disposed on the fixing part. The fixed magnets are electromagnets, whose magnetic pole directions can be controlled respectively. A moving magnet is disposed on the moving part for matching with the fixed magnet. The moving magnet is a permanent magnet. A displacement detecting sensor is disposed on the fixing part to detect the moving state of the moving part. The fixed magnet and the displacement detecting sensor are electrically connected to the control module.

In one embodiment, the displacement detecting sensors are magnetic sensors, which detect the moving state of the moving part by detecting whether the moving magnet on the moving part is moved to a position over the fixed magnet. In another embodiment, the number of displacement detecting sensors in the electromagnetic rocking chair is at least two. In another embodiment, the number of moving magnets in the electromagnetic rocking chair is at least two. In another embodiment, the number of displacement detecting sensors is at least four, such as a first displacement detecting sensor, a second displacement detecting sensor, a third displacement detecting sensor, and a fourth displacement detecting sensor, respectively. In another embodiment, the second displacement detecting sensor includes three reed switches connected in serial.

In one embodiment, the control module comprises a fourth pin of a first control chip connected to a positive pole of a first power supply; a third pin of the first control chip connected to a power indication lamp by a first resistor; a seventh pin of the first control chip connected to a switch; fifth, sixth, ninth and tenth pins of the first control chip connected to first, second, third, and fourth displacement detecting sensors, respectively; the second pin of the first control chip connected to a first triode by a second resistor; the first triode connected to second and third triodes; a second power supply connected to the first fixed magnet by the second triode; the first fixed magnet simultaneously connected to second, third, fourth and fifth diodes to rectify output; a first pin of the first control chip connected to a seventh triode by a third resistor; the seventh triode connected to sixth and eighth triodes; a third power supply connected to the second fixed magnet by the sixth triode; the second fixed magnet simultaneously connected to sixth, seventh, eighth and ninth diodes to rectify output; the fourteenth pin of the first control chip connected to an eleventh triode by a fourth resistor; the eleventh triode connected to the twelfth and thirteenth triodes; a fourth power supply connected to the third fixed magnet by the twelfth triode; the third fixed magnet simultaneously connected to tenth, eleventh, twelfth and thirteenth diode to rectify output; a twelfth pin of the first control chip connected to a fourth triode by a fifth resistor and to a fifth triode by a sixth resistor, wherein the fourth triode and the fifth triode switch the working states of the first fixed magnet and the second fixed magnet; and a thirteenth pin of the first control chip connected to a ninth triode by a seventh resistor and to a tenth triode by a eighth resistor, wherein the ninth triode and the tenth triode switch the working states of the first fixed magnet and the third fixed magnet.

In another embodiment, the control module further comprises a second control chip capable of alternately outputting a low/high electrical level when the electronic rocking chair is loaded in a static state before powered on. After a power switch is switched on, the second control chip of the control module outputs alternately the high/low electrical level. The first, second, third triodes, the sixth, seventh, eighth triodes, and the eleventh, twelfth and thirteenth triodes alternately work to cause the corresponding fixed magnet to produce an alternate magnetic field, thereby exerting a push-up force to the moving magnet.

In another embodiment, the fixing part includes a base disposed horizontally and a support frame, wherein one end of the support frame is connected to a side of the base, and an acute angle is defined between the support frame and the base in the working state. The moving part includes a bearing shelf, wherein the bearing shelf is hinged with the fixing part by a suspension rod, the moving magnet is disposed on a bottom of the bearing shelf, and the fixed magnet is located on a corresponding position on the base where the fixed magnet can exert a magnetic force to the moving magnet at different times when the moving part is moved.

The plurality of fixed magnets can be separately controlled so that a driving force relative to the moving magnet is generated to drive the moving magnet to move by controlling the fixed magnet, and the driving force and an inertial force generated during the course of rocking can together drive the motion of the moving part, such that the electromagnetic rocking chair achieves a large load driving force, with a larger range of motion for the moving part than compared to a conventional rocking chair, even when a large weight is placed on the chair. A key feature of one embodiment of the present invention is that the first magnet acts as a relay fixed magnet, which can sense a nonspecific center of gravity formed by the moving part, and exert a relay force to the moving part.

For example, in one embodiment, the number of fixed magnets is three, including a first fixed magnet, a second fixed magnet, and a third fixed magnet, where the first fixed magnet is located between the second fixed magnet and the third magnet. When the moving part is positioned on the left side of the second fixed magnet, and moves towards the second fixed magnet until the moving part is directly above the second fixed magnet, the fixed magnet exerts a repulsion force to the moving magnet to move the moving part towards the first fixed magnet. When the moving part is moved to a position directly above the first fixed magnet, the first fixed magnet exerts a repulsion force to the moving magnet, to keep the moving part moving towards the third fixed magnet. When the moving part is moved to a position directly above the third fixed magnet, the third fixed magnet exerts a repulsion force to the moving magnet, to keep the moving part moving in a direction away from the third fixed magnet. When the moving part is positioned on the right side of the third fixed magnet, and moves towards the third fixed magnet until directly above the third fixed magnet, the third fixed magnet exerts a repulsion force to the moving magnet, the moving part is moved towards the first fixed magnet. When the moving part is moved to a position directly above the first fixed magnet, the first fixed magnet exerts a repulsion force to the moving magnet, to keep the moving part moving towards the second fixed magnet. When the moving part is moved to a position directly above the second fixed magnet, the second magnet exerts a repulsion force to the moving part, to keep the moving part moving in a direction away the second fixed magnet. Back and forth movement of the electromagnetic rocking chair is performed by such a repetitive cycle.

Furthermore, the electromagnetic rocking chair of the present invention can be conveniently started up, and an example is described in the following. As described above, the displacement detecting sensor is specially designed. For example, the second displacement detecting sensor includes a plurality of reed switches connected in series. If one or more of the reed switches is switched off, the electromagnetic rocking chair is positioned directly above the third fixed magnet before being started. A direction of the repulsion force exerted to the moving magnet by the third fixed magnet is generally perpendicular to the moving direction of the moving part, so the repulsion force cannot move the moving part. At this time, by controlling energizing states of the magnetic poles of the first fixed magnet and the second fixed magnet, the first and second fixed magnet both exert repulsion forces to move the moving magnet, thereby successfully starting the electromagnetic rocking chair. If the three reed switches of the second displacement detecting sensor are all switched off, the electromagnetic rocking chair is positioned directly above the second fixed magnet before being started. A direction of the repulsion exerted to the moving magnet by the second fixed magnet is generally perpendicular to the moving direction of the moving part, and the repulsion force cannot drive the moving part to move. At this time, by controlling energizing states of the magnetic poles of the first fixed magnet and the third magnet, repulsion forces are exerted to the moving magnet by the first fixed magnet and the third fixed magnet to move the moving part, thereby successfully starting the electromagnetic rocking chair.

The reed switch used in the electromagnetic rocking chair is a specially designed magnetic sensitive switch, and may comprise two metal piece contacts that are made of soft magnetic material and are switched off when the reed switch is powered off. The reed switch may also comprise a third metal piece acting as a contact, which is usually switched off. In one embodiment, the metal piece contacts are packaged in a glass tube filled with inert gas, or they may be in a vacuum. Ends of the metal pieces installed in the glass tube in parallel may overlap and define a gap, or they may contact each other to form a normal on/off switch contact. When the metal pieces are magnetized, the normal switch-on contact is contacted or the normal switch-off contact is separated.

The main performance characteristics of the reed switch is described in the following. First, a connection line between the north pole and the south pole of the magnet is parallel to the reed switch, or an included angle defined between the connection line and the reed switch is not a right angle, or the included angle is a right angle but the magnet is directly below the metal pieces, the metal pieces can be magnetized, the normal switch-off contact is switched on, and the normal switch-on contact is separated. Second, when the included angle is a right angle and the magnet is directly below the metal pieces, the metal pieces cannot be magnetized, and the position states of the switch on/off contact remain unchanged. Third, when the included angle between the connection line and the reed switch is a right angle, and the magnet is not directly below the metal pieces, the metal pieces can be magnetized, the normal switch-off contact is switched on, and the normal switch-on contact is separated. The reed switches used in the second displacement detecting sensor are normal switch-off reed switches.

In one embodiment, the fixing part includes a base disposed generally horizontally and a support frame, wherein one end of the support frame is connected to a side of the base, and an acute angle is defined between the support frame and the base in the working state. The moving part includes a bearing shelf, wherein the bearing shelf is hinged with the fixing part by a suspension rod. In this embodiment, the structure of the electromagnetic rocking chair is stable, providing support for the largest load and preventing the electromagnetic rocking chair from swaying when the electromagnetic rocking chair is used. The moving magnet may be disposed on a bottom of the bearing shelf, while the fixed magnet may be disposed on a corresponding position on the base where the fixed magnet can exert a force to the moving magnet at different times when the moving part is moved. The configuration of the fixed magnet and the moving magnet causes a larger rocking range of the moving part, but with relatively low power consumption.

In another embodiment, the number of moving magnets is at least two, and the at least two moving magnets are disposed on a bottom of the bearing shelf. As a result of this design, as is true for all embodiments of the present invention, the electromagnetic rocking chair can rock stably with a large rocking range, but without making considerable noise as is typically associated with traditional electric cradles. When the number of moving magnets is two and the number of fixed magnets is three, a force by one or more of the fixed magnets may be exerted upon one or more of the moving magnets during movement of the moving part to avoid the unstable operation of the electromagnetic rocking chair or to avoid a decrease of the rocking range.

In another embodiment, the electromagnetic rocking chair may tolerate a deviation of the center of gravity of the moving part. For example, when the moving magnet is moved from left to right and the moving part is in the leftmost position, the moving magnet may be detected by the leftmost reed switch of the first displacement detecting sensor, and when in the rightmost position, the moving magnetic may be detected by the rightmost reed switch of the fourth displacement detecting sensor. Accordingly, the electromagnetic rocking chair of the present invention can be started as long as the moving part is in the area between the leftmost position and the rightmost position. When there are more than two moving magnets, the area between the leftmost position and the rightmost position can be increased to enable the electromagnetic rocking chair to be started successfully, even if the center of gravity of the electromagnetic rocking chair is changed.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be further explained in conjunction with the accompanying drawings in detail.

FIG. 1 is a schematic view of an electromagnetic rocking chair in a motion state in accordance with the present invention;

FIG. 2 is another schematic view of the electromagnetic rocking chair in a motion state in accordance with the present invention;

FIG. 3 is another schematic view of the electromagnetic rocking chair in a motion state in accordance with the present invention;

FIG. 4 is a front view of the electromagnetic rocking chair in accordance with the present invention;

FIG. 5 is a perspective view of the electromagnetic rocking chair in accordance with the present invention; and

FIG. 6 is a circuit diagram of a control module of the electromagnetic rocking chair in accordance with the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

As used herein, each of the following terms has the meaning associated with it in this section.

The articles “a” and “an” are used herein to refer to one or to more than one (i.e., to at least one) of the grammatical object of the article. By way of example, “an element” means one element or more than one element.

“About” as used herein when referring to a measurable value such as an amount, a temporal duration, and the like, is meant to encompass variations of ±20%, ±10%, ±5%, ±1%, and ±0.1% from the specified value, as such variations are appropriate.

Throughout this disclosure, various aspects of the invention can be presented in a range format. It should be understood that the description in range format is merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of the invention. Accordingly, the description of a range should be considered to have specifically disclosed all the possible subranges as well as individual numerical values within that range. For example, description of a range such as from 1 to 6 should be considered to have specifically disclosed subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6 etc., as well as individual numbers within that range, for example, 1, 2, 2.7, 3, 4, 5, 5.3, 6 and any whole and partial increments therebetween. This applies regardless of the breadth of the range.

The present invention relates to an electromagnetic rocking chair having a large load driving force that is capable of being smoothly started up, even when the center of gravity of the moving part is deviated. The electromagnetic rocking chair of the present invention generally includes a fixing part, a moving part moveable relative to the fixing part, and a control module for controlling at least one magnetic force exerted on the moving part. The fixing part comprises a plurality of electromagnets, at least one displacement detecting sensor, and the control module, and the moving part comprises a plurality of permanent magnets.

The plurality of fixed magnets can be separately controlled so that a driving force relative to the moving magnet is generated to drive the moving magnet to move by controlling the fixed magnet, and the driving force and an inertial force generated during the course of rocking can together drive the motion of the moving part, such that the electromagnetic rocking chair achieves a large load driving force, with a larger range of motion for the moving part than compared to a conventional rocking chair, even when a large weight is placed on the chair. As contemplated herein, the first magnet acts as a relay fixed magnet, which can sense a nonspecific center of gravity formed by the moving part and exert a relay force to the moving part.

For example, in one embodiment, the number of fixed magnets is three, including a first fixed magnet, a second fixed magnet, and a third fixed magnet, where the first fixed magnet is located between the second fixed magnet and the third magnet. When the moving part is positioned on the left side of the second fixed magnet, and moves towards the second fixed magnet until the moving part is directly above the second fixed magnet, the fixed magnet exerts a repulsion force to the moving magnet to move the moving part towards the first fixed magnet. When the moving part is moved to a position directly above the first fixed magnet, the first fixed magnet exerts a repulsion force to the moving magnet, to keep the moving part moving towards the third fixed magnet. When the moving part is moved to a position directly above the third fixed magnet, the third fixed magnet exerts a repulsion force to the moving magnet, to keep the moving part moving in a direction away from the third fixed magnet. When the moving part is positioned on the right side of the third fixed magnet and moves towards the third fixed magnet until directly above the third fixed magnet, the third fixed magnet exerts a repulsion force to the moving magnet, and the moving part is moved towards the first fixed magnet. When the moving part is moved to a position directly above the first fixed magnet, the first fixed magnet exerts a repulsion force to the moving magnet, to keep the moving part moving towards the second fixed magnet. When the moving part is moved to a position directly above the second fixed magnet, the second magnet exerts a repulsion force to the moving part, to keep the moving part moving in a direction away the second fixed magnet. Back and forth movement of the electromagnetic rocking chair is performed by such a repetitive cycle.

Furthermore, the electromagnetic rocking chair of the present invention can be conveniently started up, and an example is described in the following. In one embodiment the displacement detecting sensors are magnetic sensors, which detect the moving state of the moving part by detecting whether the moving magnet on the moving part is moved to a position over the fixed magnet. In another embodiment, the number of displacement detecting sensors in the electromagnetic rocking chair is at least two. In another embodiment, the second displacement detecting sensor includes three reed switches connected in series. For example, the second displacement detecting sensor includes a plurality of reed switches connected in series. If one or more of the reed switches is switched off, the electromagnetic rocking chair is positioned directly above the third fixed magnet before being started. A direction of the repulsion force exerted to the moving magnet by the third fixed magnet is generally perpendicular to the moving direction of the moving part, so the repulsion force cannot move the moving part. At this time, by controlling energizing states of the magnetic poles of the first fixed magnet and the second fixed magnet, the first and second fixed magnet both exert repulsion forces to move the moving magnet, thereby successfully starting the electromagnetic rocking chair. If the three reed switches of the second displacement detecting sensor are all switched off, the electromagnetic rocking chair is positioned directly above the second fixed magnet before being started. A direction of the repulsion exerted to the moving magnet by the second fixed magnet is generally perpendicular to the moving direction of the moving part, and the repulsion force cannot drive the moving part to move. At this time, by controlling energizing states of the magnetic poles of the first fixed magnet and the third magnet, repulsion forces are exerted to the moving magnet by the first fixed magnet and the third fixed magnet to move the moving part, thereby successfully starting the electromagnetic rocking chair.

The reed switch used in the electromagnetic rocking chair is a specially designed magnetic sensitive switch and may include two metal piece contacts, which are made of soft magnetic material and are switched off when the reed switch is powered off. The reed switch may also include a third metal piece acting as a contact, which is usually switched off. In one embodiment, the metal piece contacts are packaged in a glass tube filled with inert gas, or they may be in a vacuum. Ends of the metal pieces installed in the glass tube in parallel may overlap and define a gap, or they may contact each other to form a normal on/off switch contact. When the metal pieces are magnetized, the normal switch-on contact is contacted or the normal switch-off contact is separated.

The main performance characteristics of the reed switch is described in the following. First, a connection line between the north pole and the south pole of the magnet is parallel to the reed switch, or an included angle defined between the connection line and the reed switch is not a right angle, or the included angle is a right angle but the magnet is directly below the metal pieces, the metal pieces can be magnetized, the normal switch-off contact is switched on, and the normal switch-on contact is separated. Second, when the included angle is a right angle and the magnet is directly below the metal pieces, the metal pieces cannot be magnetized, and the position states of the switch on/off contact remain unchanged. Third, when the included angle between the connection line and the reed switch is a right angle, and the magnet is not directly below the metal pieces, the metal pieces can be magnetized, the normal switch-off contact is switched on, and the normal switch-on contact is separated. The reed switches used in the second displacement detecting sensor are normal switch-off reed switches.

In one embodiment, the fixing part includes a base disposed generally horizontally and a support frame, where one end of the support frame is connected to a side of the base, and an acute angle is defined between the support frame and the base in the working state. The moving part includes a bearing shelf, wherein the bearing shelf is hinged with the fixing part by a suspension rod. In this embodiment, the structure of the electromagnetic rocking chair is stable, providing support for the largest load and preventing the electromagnetic rocking chair from swaying when the electromagnetic rocking chair is used. The moving magnet may be disposed on a bottom of the bearing shelf, while the fixed magnet may be disposed on a corresponding position on the base where the fixed magnet can exert a force to the moving magnet in different times when the moving part is moved. The configuration of the fixed magnet and the moving magnet causes a larger rocking range of the moving part, but with relatively low power consumption.

In another embodiment, the number of moving magnets is at least two, and the at least two moving magnets are disposed on a bottom of the bearing shelf. In this design, as is true for all embodiments of the present invention, the electromagnetic rocking chair can rock stably with a large rocking range, and without making considerable noise as is typically heard from traditional electric cradles. When the number of moving magnets is two and the number of fixed magnets is three, a force by one or more of the fixed magnets may be exerted at an appropriate time upon one or more of the moving magnets during movement of the moving part to prevent unstable operation of the electromagnetic rocking chair or to prevent a decrease of the rocking range, or both.

In another embodiment, the electromagnetic rocking chair may tolerate a deviation of the center of gravity of the moving part. For example, in one embodiment, when the moving part is in the leftmost position, the moving magnet can be detected by the leftmost reed switch of the first displacement detecting sensor, or when in the rightmost position, the moving magnetic can be detected by the rightmost reed switch of the fourth displacement detecting sensor. The area between the leftmost position and the rightmost position is the area where the moving part can be started. When there are more than two moving magnets, the area between the leftmost position and the rightmost position can be increased to enable the electromagnetic rocking chair to be started successfully. Accordingly, the electromagnetic rocking chair of the present invention can be started even if the center of gravity of the electromagnetic rocking chair is changed, as long as the moving part is in the area between the leftmost position and the rightmost position.

Referring to FIGS. 1-3, an exemplary electromagnetic rocking chair in accordance with the present invention is shown and generally includes a fixing part 10 and a moving part 20, where moving part 20 may be moved relative to fixing part 10. As contemplated herein, fixing part 10 may include a plurality of magnets, and is not limited to any particular number, size or type of magnets. As described herein, any magnet positioned in fixing part 10 may be referred to herein as a fixing magnet. However, it should be appreciated that while a fixing magnet may in fact be “fixed” into a particular position or location within fixing part 10, such fixing magnets are not limited to being truly fixed, and may in certain embodiments allow for at least some movement within fixing part 10. For example, in the embodiment of FIGS. 1-3, three fixed magnets are disposed on the fixing part 10 and are respectively a first fixed magnet L1, a second fixed magnet L2, and a third fixed magnet L3. In one embodiment, the first fixed magnet L1, the second fixed magnet L2, and the third fixed magnet L3 are electromagnets, where the orientations of the magnetic poles of each electromagnet may be individually and independently controlled.

As contemplated herein, moving part 20 may include at least one magnet, and preferably may include a plurality of magnets. As contemplated herein, the magnets in moving part 20 are not limited to any particular number, size or type of magnets. As described herein, any magnet positioned in moving part 20 may be referred to herein as a moving magnet. However, it should be appreciated that while a moving magnet may in fact “move” relative to a fixing magnet, the moving magnets may be either fixed into a particular position or location within moving part 20, or they may in certain embodiments allow for at least some movement within moving part 20, and should therefore not be limited either way. For example, in the embodiment of FIGS. 1-3, two moving magnets 22 are shown, matched with the fixed magnets, and are disposed on the moving part 20. The two moving magnets 22 are permanent magnets.

Displacement detecting sensors may be used to detect a motion state of the moving part 20, and may be disposed on the fixing part 10. As contemplated herein, the present invention may include at least one displacement detecting sensor. Preferably, the present invention includes a plurality of displacement detecting sensors, and is not limited to any particular number of such sensors. For example, in one embodiment, the number of displacement detecting sensors is four. As shown in FIGS. 1-3, the four displacement detecting sensors are respectively a first displacement detecting sensor 121, a second displacement detecting sensor 122, a third displacement detecting sensor 123, and a fourth displacement detecting sensor 124. In one embodiment, the second displacement detecting sensor 122 includes three reed switches connected in series. The three fixed magnets and the four displacement detecting sensors may be electrically coupled to a control module, respectively.

Referring to FIGS. 4 and 5, the fixing part 10 includes a base 13 disposed horizontally and a support frame 14, with one end of the support frame 14 being connected to a side of the base 13, thereby defining an acute angle between the support frame 14 and the base 13 in the working state. The moving part 20 includes a bearing shelf 23, with the bearing shelf 23 being hingedly attached to the fixing part 10 by a suspension rod 24. The moving magnet 22 is disposed on a bottom of the bearing shelf 23, as shown in FIG. 4. The fixed magnets are disposed on a corresponding position on the base 13 where the fixed magnet can exert a force on the moving magnet 22 at different times when the moving part 20 is moved.

Referring to FIGS. 1 and 6, the electromagnetic rocking chair further includes a control module, which may be disposed on or within fixing part 10. In one embodiment, the layout of the control module may be defined as follows: a fourth pin of a first control chip U3 is coupled to a positive pole of a first power supply; a third pin of the first control chip U3 is connected to a power indication lamp D2 LED by a first resistor R6; a seventh pin of the first control chip U3 is connected to a switch S1; and fifth, sixth, ninth and tenth pins of the first control chip U3 are respectively connected to first, second, third, and fourth displacement detecting sensors 121, 122, 123, 124. Further, the second pin of the first control chip U3 is connected to a first triode Q1 by a second resistor R13; the first triode Q1 is connected to a second triode Q2 and a third triode Q3; a second power supply is connected to the first fixed magnet L1 by the second triode Q2; the first fixed magnet L1 is simultaneously connected to second, third, fourth and fifth diodes D2, D3, D4, D5 to rectify output; a first pin of the first control chip U3 is connected to a seventh triode Q7 by a third resistor R16; the seventh triode Q7 is connected to a sixth triode Q6 and an eighth triode Q8; a third power supply is connected to the second fixed magnet L2 by the sixth triode Q6; the second fixed magnet L2 is simultaneously connected to sixth, seventh, eighth and ninth diodes D6, D7, D8, D9 to rectify output; the fourteenth pin of the first control chip U3 is connected to an eleventh triode Q11 by a fourth resistor R19; the eleventh triode Q11 is connected to a twelfth triode Q12 and a thirteenth triode Q13; a fourth power supply is connected to the third fixed magnet L3 by the twelfth triode Q12; the third fixed magnet L3 is simultaneously connected to tenth, eleventh, twelfth and thirteenth diodes D10, D11, D12, D13 to rectify output; a twelfth pin of the first control chip U3 is connected to a fourth triode Q4 by a fifth resistor R15 and to a fifth triode Q5 by a sixth resistor R22, wherein the fourth triode Q4 and the fifth triode Q5 switch the working states of the first fixed magnet L1 and the second fixed magnet L2; and a thirteenth pin of the first control chip U3 is connected to a ninth triode Q9 by a seventh resistor R18, and to a tenth triode Q10 by a eighth resistor R21, wherein the ninth triode Q9 and the tenth triode Q10 switch the working states of the first fixed magnet L1 and the third fixed magnet L3.

The control module further includes a second control chip U1 being capable of alternatively outputting a low/high electrical level, when the electronic rocking chair is loaded in a static state after powered on, after a power switch is switched on, the second control chip U1 of the control module alternately outputs the high/low electrical level. The three groups, for example, the first, second, third triodes Q1, Q2, Q3 (defined as a first group triodes), the sixth, seventh, eighth triodes Q6, Q7, Q8 (defined as a second group triodes), and the eleventh, twelfth and thirteenth triodes Q11, Q12, Q13 (defined as a third group triodes), alternately work to cause the corresponding fixed magnet to produce an alternate magnetic field, thereby exerting a push-up force to the moving magnet.

The disclosures of each and every patent, patent application, and publication cited herein are hereby incorporated herein by reference in their entirety. The present invention may be embodied in other forms without departing from the spirit or novel characteristics thereof. The embodiments disclosed in this application are to be considered in all respects as illustrative and not limitative. The scope of the invention is indicated by the appended claims rather than by the foregoing description; and all changes which come within the meaning and range of equivalency of the claims are intended to be embraced therein. 

What is claimed is:
 1. An electromagnetic rocking chair comprising: a fixing part including a plurality of electromagnets and at least one sensor; a moving part being moveable relative to the fixing part, including a plurality of permanent magnets; and a control module for controlling at least one magnetic force exerted by at least one of the electromagnets on the moving part, wherein the at least one sensor is capable of detecting a state of the moving part.
 2. The electromagnetic rocking chair of claim 1, wherein the sensor is a magnetic sensor.
 3. The electromagnetic rocking chair of claim 2, wherein the magnetic sensor is configured to detect the moving state of the moving part by detecting whether at least one of the permanent magnets on the moving part is moved to a position over at least one of the electromagnets.
 4. The electromagnetic rocking chair of claim 3, wherein the number of magnetic sensors is at least two.
 5. The electromagnetic rocking chair of claim 4, wherein movement of the moving part is initiated from at least one signal sent by the control module to at least one of the electromagnets.
 6. The electromagnetic rocking chair of claim 5, wherein movement is initiated when the chair is positioned on a non-horizontal or sloping surface.
 7. The electromagnetic rocking chair of claim 5, wherein movement is initiated by activating a repulsion force from at least one of the electromagnets that is not directly underneath at least one of the permanent magnets in the moving part.
 8. The electromagnetic rocking chair of claim 1, wherein the state of the moving part is stationary.
 9. The electromagnetic rocking chair of claim 8, wherein the stationary position of the moving part is recognized by the control module to be generally above one of the electromagnets.
 10. The electromagnetic rocking chair of claim 1, wherein the state of the moving part is moving.
 11. The electromagnetic rocking chair of claim 10, wherein the moving position of the moving part is recognized by the control module to be generally above one of the electromagnets.
 12. The electromagnetic rocking chair of claim 1, wherein the number of the permanent magnets is at least two.
 13. The electromagnetic rocking chair of claim 1, wherein the number of sensors is four, and the number of permanent magnets is three.
 14. The electromagnetic rocking chair of claim 13, wherein at least one sensor comprises three reed switches connected in series.
 15. The electromagnetic rocking chair of claim 6, wherein the control module comprises: a fourth pin of a first control chip coupled to a positive pole of a first power supply; a third pin of the first control chip connected to a power indication lamp by a first resistor; a seventh pin of the first control chip connected to a switch; fifth, sixth, ninth and tenth pins of the first control chip connected to first, second, third, and fourth sensors; a second pin of the first control chip connected to a first triode by a second resistor, wherein the first triode is connected to a second triode and a third triode; a second power supply connected to a first electromagnet by the second triode, wherein the first electromagnet is simultaneously connected to a second, a third, a fourth and a fifth diode to rectify output; a first pin of the first control chip connected to a seventh triode by a third resistor, wherein the seventh triode is connected to a sixth triode and an eighth triode; a third power supply connected to the second electromagnet by the sixth triode, wherein the second electromagnet is simultaneously connected to a sixth, a seventh, an eighth and a ninth diode to rectify output; a fourteenth pin of the first control chip connected to an eleventh triode by a fourth resistor, wherein the eleventh triode is connected to a twelfth triode and a thirteenth triode; a fourth power supply connected to the third electromagnet by the twelfth triode, wherein the third electromagnet is simultaneously connected to a tenth, an eleventh, a twelfth and a thirteenth diode to rectify output; a twelfth pin of the first control chip connected to a fourth triode by a fifth resistor and to a fifth triode by a sixth resistor, wherein the fourth triode and the fifth triode switch the working states of the first electromagnet and the second electromagnet; and a thirteenth pin of the first control chip connected to a ninth triode by a seventh resistor, and to a tenth triode by a eighth resistor, wherein the ninth triode and the tenth triode switch the working states of the first electromagnet and the third electromagnet.
 16. The electromagnetic rocking chair of claim 15, wherein the control module further comprises a second control chip being capable of alternately outputting a low/high electrical level, when the electronic rocking chair is loaded in a static state before powered on, after a power switch is switched on, the second control chip of the control module alternately outputs the high/low electrical level, wherein the first, second, and third triodes are defined as a first group triodes, the sixth, seventh, and eighth triodes are defined as a second group triodes, and the eleventh, twelfth and thirteenth triodes are defined as a third group triodes, the three group triodes alternately work to cause a corresponding electromagnet to produce an alternate magnetic field, thereby exerting a push-up force to at least one of the permanent magnets.
 17. The electromagnetic rocking chair of claim 1, wherein the fixing part comprises a base disposed generally horizontal and a support frame, wherein a first end of the support frame is connected to a side of the base, and an acute angle is defined between the support frame and the base in the working state, and wherein the moving part comprises a bearing shelf, wherein the bearing shelf is hingedly attached to the fixing part at a second end by a suspension rod.
 18. The electromagnetic rocking chair of claim 17, wherein at least one of the permanent magnets is disposed on a bottom of the bearing shelf.
 19. The electromagnetic rocking chair of claim 18, wherein at least one of the electromagnets is located on the base where the electromagnet can exert a magnetic force on at least one of the permanent magnets in different time when the moving part is moved.
 20. An electromagnetic rocking chair, comprising: a base including a plurality of electromagnet and a plurality of sensors; a support frame, wherein a first end is connected to a side of the base; a bearing shelf including a plurality of permanent magnets; at least one suspension rod, wherein a first end of the at least one suspension rod is hingedly connected to a second end of the support frame, and a second end of the at least one suspension rod is connected to the bearing shelf, such that a least a portion of the bearing shelf hangs above at least a portion of the base; and a control module for controlling at least one magnetic force exerted by at least one of the electromagnets in the base. 